Razor blade hone



Oct. 2, 1934. J. R OPPENHEIMER 1,975,284

RAZOR BLADE HONE' Filed March 14, 1931 2 Sheets-Sheet. l

Patented Oct. 2, 1934 isvszsi RAZOR BLADE noun Julius L. Oppenheimer,Bridgeport, ctini. Application March 14;'19 3-1,- Serial No. 522,570

" a razor blade, and one with which practically all types of safetyrazor blades may be sharpened. Another object is t6 providea sharpeningdevice which may be manuiaeture'd and sold at relatively low cost, andwillbe effective for a long time.

With the foregoing and other objects in view, a I blades, are however,as a rule so thin andfle'xiblei the invention consists in certain. novelfeatures of construction of a device for honing safety razor blades, andan improved method of honing these blades as will be more fullydisclosed in connection with the accompanying drawings. In thesedrawings: a Fig'. 1 is a top plan view of a preferred form of1iiydevice;' v v '25 Fig.2 is a; side elevation thereof;

Figs. 3, 4 and 5 are longitudinal sections subst'antially on lines 33',4-4 and 5-5 respec tively Of Fig. 1; a

v Fig. 6 is an end view of'the device in Fig. l; $0 Figs. 7 and 8 aret'ransv'er'se sections susstsn: tially on lines 7+7 and line 8-8respectively. of Fig. l; 7

Figs.- 9 and 10 are transverse sections substan-.

tiallyonlirie 9-9 of Fig. l, but showing how the blade can be sharpenedby use either direction on the hone; A V

Fig; 11 is a partial section and partialend elevation of the honereversed showing how it may be used for sharpening a blade having asingle 4 cutting edge; and with abound rear edge;

Figs. 12 and 13 show how the device may be employed as a detachableseparate element for use with the'main block for'finishing purposesjFigs. l4 and 15 are longitudinal and transverse central lsectionsshowing "modified sharpening surfacesjl i'g l4"b'eing" a sectionlongitudinally on line l=l"14 of Fig. 15, and Fig- 15 being a? sectiontransversely line 15-45 of Fig. 14f 5"0 modification, the plane ofsection being indicated in each case by the correspondingly numberedlines;

"Figs. l6 'andlll7 are similar sections-of another 7 Figs. 18 to'2 3 arelon'gitudinal and transverse SC ti6 XYS of thredlffer llt modificilllfisthe SE6 7 claims. (cl. 51-2111 ti'ons being taken on the similarlynumbered lines of the various figures;

Fig. 24 is a top plan View of still another modi fi'catiomand M l Figs.25 and 26 are transversese'ctions substanso" tially on lines 25 and 26respectively of Fig. 24.

As is well known the usual safety razor blades are made of very thinsteel, and they are made either with single or double cutting edges. Dueto their construction and shape it is difficult to properly sharpen andhone these blades when they become dulled in use, and therefore it iscommon practice to throw them away after being used two or three times.This practice is of course expensive and it is wasteful, because theblades can] be honed or resharpened. These that it iS difficult to h'bldthem uniformly against the sharpening surface, and therefore it will beevident that under these circumstances the blade will not be uniformlysharpened, but for a given honing certain portions of the edge will bemore. thoroughly honedthan others. This is particu larlytrue of the verythin blades now found on the market, in which unless'firml'y c amped,the st cutting edges are warped laterally. I y Y I have, however,discovered that if the blades are flexedlongitudinally, that is, thecutting edge is curved laterally to the plane of the blade, then thiscutting edge is stiffened and helduniforin 35' throughout- Therefore, itwill be evident that if the blade is honed when in this condition theedge or edges can. be uniformly sharpened throughout the entire lengthof these" cutting edges.

Thus the gist of the present invention is the sharpeningor honing of theblade edge or edges while they are flexed longitudinally and laterally.of the plane of the blade so that the blade is honed. whi'le the cuttingedge is curved la'terally to giv' it strength and stiffnessand the,bevel for the entire length of the cutting edge is held onthe Y surfaceof the hone with uniform pressure, thus giving a; uniform honing at allpoints of the edge.

This can be most effectively and easily secured by means ofa" surfacehaving a combination of curves, that is the surface curves in onedirection soas to fitor properly engage" the bevel or bevels'j; at thesides of the cutting e'd'g'eforthe sharpen ing effect; which curve isthere ore transverselyl0 of the blade, and then the surface is alsocurved lOngitudinally 0f the blade so that when fllblad is pressedagainst the surface to bring the bevel in engagement therewith, theblade is fle'iiedlon m gitudi'nally, that is" the cutting edge is curved1st:

indicated in dotted lines 29, although, of course,

erally to the plane of the blade so that it is given increased strengthand stiffness because of this flexing to remove the warping of the bladeat the cutting edge, and it will engage the honing surface with uniformpressure throughout the entire length of the cutting edge. It willtherefore be obvious it will be uniformly honed or sharpened throughoutthe entire length of the blade.

This effect can be secured in a great number of difierent ways. I haveillustrated in the drawings a number of ways of securing these resultsto give a comprehensive idea of how this improved honing may be secured.Referring first to Figs. 1 to 10 my improved hone or sharpening devicecomprises a body member 26 of any suitable material for honing orsharpening the edges of the razor blade. Thus for example, it may be ofnatural oil or water, stone, artificial stone such as carborundum or itmay be of other materials such as glass, and it is shown in thesefigures as being of a slab or block of this material, although othershapes may be used if desired. As a matter of fact it may be of anyshape or size for best handling and convenience to secure the honing orsharpening of the blade in the manner in Figs. 6 to 10. These curves maybe the same or on the same radii but they are preferably different or ondifferent radii. Thus as indicated in Fig. 1 with the longer blade 28 insharpening position'it may be placed as indicated in full lines, and ifa shorter blade it may be turned at right angles as the shorterblade maybe sharpened in a longitudinal position the same as blade 28. Thus forexample, for the blade 28 in the position shown,

the surface 27 should be curved transversely so as to engage the bevels30 adjacent the cutting edges 31 as indicated in Fig. 9. If all theblades were sharpened in this position the surface could be curvedlongitudinally in practically anyway desired so long as it flexed thecutting edges of the blade longitudinally as indicated in Fig. 4.

In this specific illustration, however, I have shown the surface 27 ascurved both transversely and longitudinally to engage or fit the bevelsfor the proper sharpening of the cutting edges so that the blade can behoned in either position, and

the two curvatures longitudinally and transversely can be the same orthey can be different so that the transverse curvature may fit the bevelof one make of blade, while the longitudinal curva--v ture is such as tofit or engage the bevel of another malre of blade. But it is to bedistinctly understood that in either case the sharpening surface 27 isso shaped in one direction as to bevels on the blade for proper sharptoflex or curve the blade longitudinally, that is to bend the bladelaterally to the plane of the blade as indicated in Fig. 4.

In use the surface 27 may be moistened as for example 'withwater, latheror oil, etc. depending upon the material of which the device is made,and then the blade to be sharpened is placed on the surface, either inthe full line or the dotted line positions of Fig. l as shown. If it isin the full line position the user places his fingers on the top of theblade and then presses downwardly on it. This brings the bevel for theentire length of the cutting edges against the surface 27. As the bladesare much longer than their width they will remain substantially flat inthe transverse plane as shown in Fig. 9 so that the cutting edges are incontact with the surface 27, that is the bevels will rest on thesurface, and as the blade is moved over the surface this bevel will beground off to give the sharpening effect. This pressure, however, on thetop of the blade will flex it downwardly in the center as indicated inFig. 4 so that is is curved longitudinally in a direction laterally tothe plane of the blade. It will be evident therefore that the cuttingedges are correspondingly curved as they engage the. surface 27, andthey therefore engage this surface throughout the entire length of theblade. This curving of the edge of the blade and the portion of theblade adjacent thereto stiffens and strengthens this edge and adjacentportions so that the edge and bevel rest with uniform pressurethroughout their entire lengths on the sharpening surface 27. Also thecurving of the body of the blade stiffens the blade so that it'assistsin stiffening the edge portions. The operator now can shift the bladetransversely back and forth as indicated by the arrows 32 Figs. 1 and 9very quickly giving a thorough and uniform sharpening to both edges ofthe blade simultaneously, and forming the minute teeth in such a way asto give the best cutting edge. After one side is sharpened the blade ismerely turned over and the sameoperation performed on the other side. Ifthe blade is placed transversely as indicated in dotted lines Fig. 1,then it is shifted backwardly and forwardly as indicated by the dottedarrows 33 and the blade will be curved longitudinally as indicated inFig. 10.

In this form illustrated in Figs. 1 to 10, the

surface 27 is so formed that the curvature at the top of anylongitudinal section is on the same radius. Thus in each of Figs. 1, 2,3 and 5 the curvatures indicated at 27, which is the intersecin thetransverse sections of Figs. 7, 8, 9 and 10 are all the same radius.This is the preferred construction because in the lateral movements ofthe blade on the curved surface during the sharpening operation there isno change in the. curvature, and therefore there is no change in thecurvature of the blade or the engagement of the bevels on the sharpeningsurface in any position. However, the desired effect of uniform honingthroughout the entire length of the cutting edge can be secured if thesecurvatures vary as will be more fully described in connection with otherfigures of the drawings.

As shown in Figs. 1 to 11 the block may be double, that is, it may haveone surface on the top and another surface on the bottom, the specificcombination shown comprises on the bottom a surface more particularlydesigned for sharpening or honing the singleedge blade indicated at 3Fig. 11, having one edge bound in a U-shape clip 35. It will this typeof blade, the whole blade can not be readily flexed longitudinally. Ihave, therefore, provided two oppositely inclined surfaces 36 which maybe either convex or concave, those illustrated being convex so as togive a hollow ground or convex bevel on the razor blade. These surfaces36 are curved longitudinally either concave or convex preferablyconcave, as shown in Figs. 3 to 5, or they can be straight for use insharpening '5 thicker or heavier blades which would notne'ed flexinglongitudinally. These two surfaces 36 are separated at the center by aconvex rib 37 extending longitudinally, but straight in the longitudinaldirection. Thus the rib 37 provides a guide for the bound andstiffenededge of the blade asv indicated in Fig.11, while the bevel adjacent thecutting edge rests on one of the surfaces 36, and by pressing down onthe blade the cutting edge 38. is curved longitudinally to fit thelongitudinal curvature of the surface 36 as indicated, while the boundedge or back may remain straight. Thus the effect of stiffening andstrengthening the cutting edge of this single edge blade with thestiffened back edge is secured in 2i) the same manner as is secured withthe double edgeblade on the top surface 27. The blade may be honed byshifting longitudinally on the body, but a better result is secured byshifting it in short strokes transversely as indicated by the 251 arrows39 in Fig. 11, as this provides the edge with the microscopic teethdesired for the best cutting effect. This double surface may also beused for sharpening the double edged blade by simply placing the bladeso that the two bevels engage the two surfaces 36.

In Figs. 12 and 13 is shown how a single device may be used for givingtwo different effects, that is, the body 26 may be the same as that inFig. 1, and of any suitable material such as natural stone orcarborundum, and then a separate element may be shaped of some differentmaterial, such for example as glass. This element 40 is madecomparatively thin and curved on the bottom surface 41 to fit the topsurface 27 of the I'D-"block 26, while the top surface 42 of the block40 may be of the same or different surface material as the surface 27.Thus, the block 26 and member 40 can be sold in nested relation as shownin Fig. 13, or they can be sold as sepaffii'grate elements. If used incombination the element 40 can be removed and the blade given a firstsharpening on the surface 27 of the block 26, and then the element 40can be placed in the dotted line position, and the blade given a fin-5or ishing sharpening on the element 40.

The showings of Figs. 14 to 26 indicate various modifications that canbe used. Thus the sharpening surface need not be curved or arched oreven on a continuous curvature of the same rafifirg dius, but thecurvatures may vary. Thus as shown in Figs. 14 and 15 the centralportion at 43 may be quite a sharp curve and toward the higher parts ofthe surface as indicated at 44 and the curvature may be on aconsiderably larger eee radius, or they may vary continuously.

In Figs. 16 and 1'7 is shown how the double concave surface can be usedto hone a single edged blade 34 with the opposite edge bound by a U-shaped clip 35. Here the surface 44, 45 is curved longitudinallysufficient to permit the bevel of the cutting edge to engage the surfaceas shown in Fig. 16 when the binding clip 35 engages the honing surface.This surface is curved in the opposite direction, or longitudinally ofthe blade 7x3; with a relatively small curvature as shown in Fig. 17.Thus although the clip 35 does not flex longitudinally of the blade thecutting edge and portion of the blade adjacent thereto is flexedlongitudinally, as shown in Figs. 16 and 17, sufii- 7'51 ciently to givethe desired strengthening and stiffening of the cutting edge andportions adjacent thereto to give uniform honing throughout its entirelength, the same as in the other forms for the double edged blade.

In Figs; 18 and 19 is shown how either or both sides may be raised asindicated at 46 to retain water or oil on the surface. It is not evennecessary that the sharpening surface be curved in both directions. Thusin Figs. 20 and 21 the sharpening surface includes two sides 51 whichare straight or flat in the transverse directions, but inclined inopposite direct-ions so as to engage the bevels of the blade; but in thelongitudinal direction, they are curved as indicated in Fig. 26 to causethe longitudinal 9?) flexing of the blade in a direction laterally ofthe plane thereof to give the stiffening and strengthening effect abovedescribed.

Furthermore, it is not necessary that both curvatures be concavecurvatures;.in Figs. 1 to 11 it is shown how the surfaces 36 can beconvex togive a concave or hollow ground effect to thebevels of thecutting edges. In Figs. 22 and 23 is illustrated how the blade can becurvedlongi-i tudinally by a convex curve. Thus in this figure, theblock or body member has a top surface 47 concaved transversely asindicated at 43 to properly engage the bevels of the blade 48, but thissurface is convex in the longitudinal direction as indicated in Fig. 22.This convex curvature flexes the blade longitudinally during thesharpening operation to give the stiffening and strengthening effect foruniform honing throughout the entire length of the cutting edges, thesame as if this surface was concave in this direction. The doubleconcave surfaces are preferred, however, as these surfaces retain thewater, lather, oil or other moistening material so that it will not runoff of the surface of the hone during the honing operation.

In Figs. 24, 25 and 26 is shown a body member 49 in which the sharpeningsurface 50 is a part of a spherical surface and will thus be curvedsimilarly in all directions. In this device, however, the surface mustbe curved to properly engage the bevels to give the desired sharpeningeffect, and the same curvature longitudinally of the blade will alsogive the desired longitudinal flexing to produce the stiffening andstrengthening effect for uniform sharpening of the cutting edgesthroughout their entire lengths.

It will be evident that other specific arrangements of the surfaces andshapes of the body member may be used so long as the sharpening surfaceis so shaped as to engage the bevel or bevels at the cutting edge oredges to give the desired sharpening effect, and at the same time, theblade is flexed longitudinally or that is the cutting edge or edges isor are curved laterally to the plane of the blade to stiffen orstrengthen this edge or edges to give a uniform sharpening effectthroughout the entire length of the edge.

Having thus set forth the nature of my invention, what I claim is:

1. A sharpening device for safety razor blades comprising a body havingtwo oppositely inclined convex surfaces to engage the bevels at thecutting edges of the blade when it is in sharpening position, saidsurfaces being concaved longitudinally so that when pressure is appliedto the blade to bring it to sharpening position the edges of the bladeare flexed longitudinally.

2. The method of honing a safety razor blade which consists in placingthe blade on a honing m. surface concaved both transversely and longitu-150 dinally of the blade applying pressure to the blade to flex itlongitudinally in a lateral directionto bring the beveled surfacesadjacent the cutting edges against the honing surface for their entirelengths, and then shifting the blade on the honing surface in adirection transversely of the blade.

3. The method of honing a safety razor blade which consists in applyingpressure on the blade and shifting the blade transversely on a surfaceof a material capable of putting a shaving edge on the blade shaped toengage the bevel at the cutting edge of the blade and also curvedlongitudinally of the blade so that with pressure applied to the bladethe cutting edge is flexed longitudinally in a direction laterally ofthe plane of the blade by the pressure of the blade against the surface.

4. The method of honing a safety razor blade which consists in applyingpressure on the blade While on a surface of a material capable ofputting a shaving edge on the blade shaped to engage the bevel at thecutting edge of the blade and alsocurved longitudinally of the blade sothat with pressure applied to the blade the cutting edge is flexedlongitudinally in a direction laterally of the plane of the blade bypressure of the blade against the surface, and then causing relativemovement between the blade and the surface in a direction transverselyof the blade While it is so flexed.

5. The method for sharpening a blade that consists in curving the bladelengthwise of its edge and also in a direction transverse of said edge,and then efiecting a frictional action between the blade and asharpening surface. s

6. The method for sharpening a flexible blade that consists in applyingthe blade to a spherical concaved surface to flex said blade in lateraldirections, and then rubbing the blade against such surface.

7. The method for sharpening a flexible blade that consists in applyingthe blade to a surface concaved in all directions to flex said blade inlateral directions, and then rubbing the blade against such surface.

JULIUS P. L. OPPENHEIMER.

